But you don't have any evidence, or even anything that might even suggest your case. It just seems more likely to me that there would simply be less money in the industry if it were just PCs, and that would make more difference than the state of the hardware.

I can easily identify games that were scaled back due to consoles. But would those games have been made at all if they were going to be PC only? It seems improbable, because you're basically talking about half or less of the profit and therefore a smaller budget. Instead of AAA games like Skyrim you get AA or A games like, I guess, S.T.A.L.K.E.R., and still don't end up pushing the envelope.

Further, if hardware did advance more quickly, the games taking advantage of it would cost more to make, too. It's likely that hardware also hasn't jumped forward because there's no corresponding market expansion that would pay for the additional work required to make bigger and better games. There are commenters on Blue's who already feel that publishers are chasing pipe dreams launching as many high budget games as they already do.